I've only seen deer movement durring heavy thunder once. The deer were totally freaked out and ran past me at about 60 mph. I've also seen a deer in a hail storm run flat out too. I actually thought this buck killed himself by running into a big oak tree! He went down and stayed down for at least 30 seconds, then he got back up and kind of staggered off. I could have shot him but had already filled my buck tag. I just sat and watched with my jaw wide open. Never seen anything quite like it before.
This summer a tornado went through about 5 miles of where I used to gun hunt. They found a lot of dead deer in an area that had a lot of young pine trees and low ground cover. Like a patch of xmas trees 10-15 feet tall and branches all the way to the ground. This would tell me that's what kind of cover deer hide in when the weather gets bad. I've hunted those pines and you'de be lucky to get a shot at anything more than 15 yards away. The tornado flattened a strip 1/2 mile wide and went for miles. One small area had over 100 dead deer.